1- BASIC PRINCIPLES AND PRACTICES Flashcards
A quantitative science that is concerned with measurement of amounts of biologically important substances in body fluids.
CLINICAL CHEMISTRY
Examples of analytes in CC
Ions, salts and minerals
Metabolites
Therapeutic drugs
Drugs of abuse
Proteins
Enzymes
Lipoproteins
Diabetes marker
Specific samples of analytes that are Ions, salts and minerals
potassium, sodium, calcium, chloride, phosphorus, lead, iron
Specific samples of analytes that are Metabolites
glucose, urea, bilirubin, creatinine, triglycerides, cholesterol
Specific samples of analytes that are Therapeutic drugs
digoxin, vancomycin, theophylline, phenytoin, valproic acid
Specific samples of analytes that are Drugs of abuse
cocaine, barbiturates, amphetamines, opiates, cannabinoids
Specific samples of analytes that are Proteins
albumin, haptoglobin, transferrin,
ferritin
Specific samples of analytes that are Lipoproteins
Lipoprotein (a), HDL, LDL
Specific samples of analytes that are Enzymes
alanine aminotransferase, aspartate aminotransferase, amylase, lipase
Specific samples of analytes that are Diabetes marker
Hemoglobin A1c
It is to be remembered that ________ are analyzed in the laboratory while the __________ are measured and quantified
specimens or samples
analytes
When an individual test is not sufficient to assess the medical condition of the patient, combination of several test may be used, which is known as
Panel or profile
Panel or profile examples
Hepatic Panel (Liver Profile)
Lipid Profile
These tests are used to determine hepatic
dysfunction or hepatic damage
Hepatic panel
Which analytes are quantified in a Hepatic Panel (Liver Profile)
Albumin
Total Protein
Alkaline phosphatase
Alanine aminotransferase
Aspartate aminotransferase
Total Bilirubin
Direct Bilirubin
Which analytes are quantified in a Lipid Profile
Total Cholesterol
LDL Cholesterol
HDL Cholesterol
Triglycerides
Results of clinical chemistry tests are compared to what in order to determine if it is normal
reference intervals or a medical decision level (MDL)
MDL that is not a clinical entity but an
indication that the patient is at risk of having diabetes mellitus
Impaired fasting glucose
MDL that means the patient has
diabetes mellitus
Provisional diabetes diagnosis
Normal Fasting Glucose range
FPG 70-99 mg/dl
3.9 - 5.5 mmol/L
Impaired Fasting Glucose range
FPG 100-125 mg/dl
5.6-6.9 mmol/L
Provisional Diabetes Diagnosis ranged
FPG >126 mg/dl
>7.0 mmol/L
2 components of a quantitative laboratory result
Actual value
Unit of expression
components of a quantitative laboratory result that describes the numeric value
Actual value
components of a quantitative laboratory result that describes the physical quantity or
dimension (e.g. mass, volume, length or time)
Unit of expression
o Adopted internationally in 1960
o Preferred in scientific literature and clinical
laboratories
o Based on metric system
o Only system used in many countries
Système Internationale d’Unités (SI)
a compound or mixture added to a system to start or test a chemical reaction
reagent
Type of chemicals that are best for lab use
Analytic reagent grade (AR) and ultrapure
CHEMICALS USED FOR REAGENT PREPARATION
Analytic Reagent (AR) Grade
Ultrapure Reagent
Chemically Pure (CP)/ Pure Grade
Technical/ Commercial Grade
o Must meet specifications set of the American Chemical Society (ACS)
o Must have labels with the initials AR or ACS or the term For laboratory use or ACS Standard-Grade Reference Materials
Analytic Reagent (AR) Grade
Analytic Reagent (AR) Grade are commonly used for?
calibration of instruments
In which analysis do we use analytic reagent grade
For trace metal analysis and preparation of standard solution
chemical grade that is put through additional purification procedures
Ultrapure Reagent
Ultrapure Reagent for use in specific procedures such as
chromatography, atomic absorption, immunoassays, and molecular diagnostics
Labels attached to ultrapure reagents
with designations of HPLC (high performance
liquid chromatography) or chromatographic
Impurity limitations are not stated and preparation is not uniform
Not recommended for research & analytical chemistry
Chemically Pure (CP)/ Pure Grade
Since impurity limitations of chemically pure/ pure grade reagents are not stated, Purity is assessed by measurement of
melting point or boiling point
o Primarily used in manufacturing
o Should never be used in the clinical laboratory
Technical/ Commercial Grade
Technical/Commercial grade is handled by
United States Pharmacopoeia (USP) and National Formulary (NF)
Technical/Commercial grade is primarily used for
Drug manufacturing
A major source of safety information for employees
OSHA Federal Hazard Communication Standard
Requires that all employees have a right to know all about the chemical hazards present in their workplace
MATERIAL SAFETY DATA SHEET (MSDS)
Information contained in an MSDS includes the following:
o Physical and chemical characteristics
o Fire and explosion potential
o Reactivity potential
o Health hazards and emergency first aid procedures
When there will be splattering or splashing, what are the emergency first aid procedures
o Methods for safe handling and disposal
o Primary routes of entry
o Exposure limits and carcinogenic potential
Solution containing known concentration of a particular chemical or analyte
Standard solution/ Standards
Highly purified chemical that can be measured directly to produce substance of exact known concentration & purity
Primary Standard
Primary Standard American Chemical Society (ACS) purity tolerances
100±0.02%
certified the use of standard reference materials (SRMs) instead of ACS primary standards
National Institute of Standards and Testing (NIST)
Substance of lower purity, with its concentration determined by comparison with primary standard
SECONDARY STANDARD
Composed of the glucose reagent and the
glucose standard
used when performing enzymatic method of
glucose determination
o Glucose oxidase method of glucose
determination
Glucose (oxidase) liquid reagent
There are two (2) organizations providing guidelines for proper chemical selection and reagent preparation
o College of American Pathologists (CAP)
o Clinical and Laboratory Standards Institute (CLSI)
Clinical and Laboratory Standards Institute (CLSI) Formerly known as the
National Committee for Clinical Laboratory Standards (NCCLS)
most frequently used reagent in clinical laboratory
Water
Water is used
To prepare reagents
As diluent for controls and standards
To flush and clean the internal components of
analyzers or of instruments in the Clinical Chemistry laboratory
To wash and rinse laboratory glassware (cluster purity)
Labs use what grade of water
Reagent grade water
6 types of reagent grade water (CLSI):
o Clinical laboratory reagent water (CLRW)
o Special reagent water (SRW)
o Instrument feed water
o Water supplied by method manufacturer
o Autoclave and wash water
o Commercially bottled purified water
Can be of use in place of Type 1 and Type 2 water
Clinical laboratory reagent water (CLRW)
Satisfactory replacement for Type 3 water
Autoclave and wash water
Water For test methods or analytical procedures requiring minimum interference
Type 1
Type 1 water is used for test like
Flame photometry,
AAS (Atomic Absorption Spectrometry)
blood gases and pH (analysis)
enzyme studies
electrolyte testing
HPLC (high performance liquid chromatography)
trace metal and iron studies
Water typed used for Reagent, quality control, and standard preparation
Type 2 water
type 2 water is usually used in tests like
Hematology, Microbiology, Immunology, and
Chemistry analysis
Water type used for glassware washing
Type 3
Type 3 water is commonly used in
UA (urinalysis), Parasitology, and Histology
Indicator of ionic content of purified water
Resistivity
Type 1 water must have a resistivity of
> 10 MΩ
MONITORING WATER PURITY what factors
Resistivity
Bacterial content (count)
pH
Silica content
Organic contaminants
Most commonly found organisms after purification process are
gram-negative gut (ex. E. coli)
Crystalline compound that is common constituent in rocks, minerals & sand
Silica
Organic contaminants
Phenolic compounds, petroleum, pesticides
METHODS OF WATER PURIFICATION
Prefiltration
Distillation
Reverse osmosis
Deionization
uses activated charcoal to remove organic materials and a submicron filter or a filter that would remove substances larger than the filter’s pores
Prefiltration
Under this method, water is first heated to the boiling point and the water vapor rises to the condenser (glass tube with glass coils) and the vapor is converted to liquid state and then is collected and stored in the storage tank
Distillation
This method is the oldest method of water purification’
Distillation
Distillation and Reverse osmosis can produce what type of water when additional filtration is added
Type 1
Uses pressure (high pressure) to force water through a semi permeable membrane
This filter removes 95% to 99% of organic
compounds, bacteria and other particulate matter and about 95% of all ionized and dissolved materials
Reverse osmosis
This method uses bead-like resin materials (ion
exchange resins (cation resin and anion resin))
Ion present in the water sample are exchanged for other ions which are fixed to the beads
Deionization
Cation resin:
Anion resin:
Cation resin: hydrogen ion (attached to the resin)
Anion resin: hydroxyl ion (fixed to the resin)
A reagent grade water can be obtained by what specific order of filtration
Prefiltration
Reverse osmosis
Deionization
0.2mm filter or more restrictive filtration process
TYPES OF GLASSWARE
Borosilicate glass
Corex
Vycor
Low actinic glass
Standard Flint Glass
Most common type of glassware in volume
measurement
Borosilicate glass
Borosilicate glass is free from which group of elements
magnesium-lime zinc group of elements, heavy metals, arsenic, and antimony
Borosilicate glass commercial types
Pyrex and Kimax
o A special alumina-silicate glass that has been
strengthened chemically rather than thermally
o Characterized by high degree of chemical resistance
o 6 times stronger than borosilicate
corex
o Recommended use for applications involving high temperature, drastic heat shock, and extreme chemical treatment with acid and alkali
o Acid and alkali resistant
Vycor
o Amber or red color added as integral part of the glass
o Gives maximum protection to light sensitive
materials (bilirubin)
Low actinic glass
Which types of glass has high thermal resistance
Borosilicate glass and Low actinic glass
o Made up of soda-lime glass and a mixture of calcium, silicon, and sodium oxides
o Poor resistance to high temperature
Standard Flint Glass
TYPES OF PLASTICWARE
Polypropylene
Polyethylene
Polycarbonate
Polystyrene
Teflon
o Flexible or rigid, is chemically resistant, and can be autoclaved
o Used in the manufacturing of plastic pipet tips, specimen tubes, and test tubes
o Can withstand temperatures down to - 190ᵒC
Polypropylene
Type of plastic that is
Used in the manufacturing of test tubes, bottles, graduated tubes, stoppers, disposable transfer pipets, volumetric pipets, and test tube racks
Polyethylene
Type of plastic that is
o Used to manufacture tubes for centrifugation, graduated cylinders, and flasks
o Useable temp range is - 100ᵒC to +160ᵒC
Polycarbonate
Type of plastic that is
o Used to manufacture capped graduated tubes and test tubes
o Rigid, clear type of plastic which should not be autoclaved
o Will crack and splinter when crushed
o Not resistant to hydrocarbons, ketones, and alcohols
Polystyrene
Type of plastic used
o For manufacturing stirring bars, tubing, cryogenic vials, and bottle cap liners
o -270ᵒC to +255ᵒC
o Resistant to a wide range of chemical classes
Teflon
Most commonly used measuring or graduated pipet in CC
Serologic and Mohr pipet
